What outdrive do you have? If you have a Volvo, then the Volvo Viper (I think that is the name) is a good prop. Otherwise, I would look at a Mercury High 5 as the best wakeboarding prop. I used to have a 202BR and the owners forum on Crownline.com is very active and helpful. You may want to try there for advice too.

Now, that said, with a small V8 and a 20' CL, I'd run around a 19" or so at a mile high. That would probably equate to a 21" at sea level.

With weight, go with a 19"

You'll have to test a few props. Period. Get with a good prop dealer adn they'll let you demo props until you find the right one. You demo deposit should go to a prop purchase. Figure on a couple hundred for a good prop.

I agree with the statement about thinnnig, but to me, that's a no brainer. An SS prop SHOULD automatically be thinner than Alum. Do you know of any SS manufacturers that don't? I'm not flaming, but I want to stay away from them if I need a new prop.

My buddy bought a boat with a volvo penta SX 190 hp(really OMC Cobra). I ended up buy the same boat. When he killed his prop, his marina sold him a SST replacement.

He brought the SST prop to my cottage and we tried it out on my boat. The props were identical... the only way you could tell them apart was the weight.

We ran a couple of tests; time to 20 mph and top speed. There was no difference! I felt bad for my buddy… but there was no difference at all.. maybe Al was a tenth faster hard to say!

After that I decided that unless the prop shape took advantage of the material there was no point. Any argument about being stiffer just doesn't wash with me.

Anyway... your last point was right on... "try a couple of props" Some of my friends race hydroplanes (very seriously) and there is a bit of a black art to props.

Oh and my final comment... most salesmen don't no jack about props....

So and I quote "You'll have to test a few props. Period. Get with a good prop dealer and they'll let you demo props until you find the right one. You demo deposit should go to a prop purchase. Figure on a couple hundred for a good prop."

I'll probably get flamed for this but I run a Quicksilver pitch switching prop on my I/O. It's like the equivilent of a 15 pitch to start, and then switchs to a 21 pitch. While I'm boarding, it usually stays at the lower pitch which is nice because the boat is easier to control speed wise there. But when we're just cruising, it switches to the 21, and then we can get a good cruise speed out of it too. Best of both worlds for "my" boat, but you'd have to try it on yours.

i thought aluminum props had to be reshaped after a year or so because they tend to loose their cup where ss wont erling, what the others said, what outdrive is on it? I dont realy care what the rpms are like at full throttle, for wakeboarding your concerned with time to plane and holding speed. Ive got a 3400 lb 20'monterey with a merc 240 and a 19" highfive. Works great for me, maybe if i added alot more weight all the time id go for a lower pitch but???